Estrogen equivalent concentration of individual isomer-specific 4-nonylphenol in Ariake sea water, Japan

Concentrations of 4-nonylphenol (NP) were determined by isomer-specific quantification of individual NP isomers based on relative response factor (RRF) quantification with GC–MS in combination with steam distillation extraction. Concentrations of NP in the Ariake Sea decreased with distance from the river mouth (St.A; 49 ng NP/l) to offshore areas (St.C; 11 ng NP/l). Even the least concentration in water from St.C in Ariake Sea was sufficient to have adverse effects on barnacles. The isomers, NP1–NP14 were separated by GC–PFC and identified structurally with NMR. The isomers varied in estrogenic activity with NP7 exhibiting the greatest estrogenic activity with a potency that was approximately 1.9 × 10⁻³ that of 17β-estradiol (E2) in recombinant yeast screen system. The coefficient of variation (CV) of NP isomer’s concentrations among three samples at St.A, B and C were 4–75%. This suggests that NP isomers might be independently degraded in aquatic environmental samples. The predicted estrogenic activity of measured concentrations of NP in Ariake Sea was 2.7–3.0-fold greater than the measured estrogen agonist activity.     

Dynamic non-linear analysis of reinforced concrete shear wall by finite element method with explicit analytical procedure

A numerical procedure for a dynamic non-linear finite element analysis is proposed here to analyse three-dimensional reinforced concrete shear wall structures subjected to earthquake motions. A shear wall is modelled as a quasi-three dimensional structure which is composed of plane elements considering the in-plane stiffness of orthogonal flange panels. The proposed constitutive model is based on the non-linearity of reinforcement and concrete in which the tension stiffening in tension and the degradation of stiffness and strength in compression of concrete after cracking are considered. The acceleration-pulse method, which is a kind of explicit analytical procedure, is employed to solve the non-linear dynamic equations, where the dynamic equation can be solved without stiffness matrix and so the iterative procedure is not necessary for descending portion of stress–strain relationship caused by cracking and softening after compressive strength in concrete. The damping effect is considered by assuming equivalent viscous damping which can give good cyclic behaviours of inertia force vs. displacement relationships. This analytical method was applied to a test specimen of a reinforced concrete shear wall with a H-shaped section which was vibrated up to failure by using a large-scale shaking table with high -performance in Japan. The test was performed as one of the dynamic model tests for evaluation of seismic behaviour of nuclear reactor buildings. The calculations were performed sequentially from the elastic range to failure. The comparison with the test results shows that this approach has good accuracy. © 1997 by John Wiley & Sons Ltd     

Variations in atmospheric CO2 at the Meteorological Research Institute, Tsukuba, Japan

Since April 1986, measurements of the CO₂ concentration in the surface air have been conducted at the Meteorological Research Institure (MRI, 36°04 N, 140°07 E, 25 m above sea level) in Tsukuba, located 50 km northeast of Tokyo, Japan. The CO₂ data measured over times between 11:00 Japan Standard Time (JST) and 16:00 JST (C _N ) were considered to be representative of the air (within a few ppmv) in the planetary boundary layer. To evaluate the representative CO₂ level on a spatial scale larger than that of the C _N record, the CO₂ data with hour-to-hour variation less than 1 ppmv were selected (C _P ). Comparison of these data with those of Ryori (39°02 N, 141°50 E), a continental station operated by the Japan Meteorological Agency, indicates that the C _P record provides a representative CO₂ level in the air on spatial scales of at least a few hundred kilometers.The C _N record allows an investigation of the internanual changes in photosynthesis/respiration against changes in climatological parameters. Within a small temperature anomaly (ca.±1 °C) respiration is sensitive to the temperature change, while photosynthesis is less sensitive. When the temperature anomaly is large, however, photosynthesis and respiration tend to be competitive.     

High-pressure and high-temperature stability of chlorite and 23-Å phase in the natural chlorite and synthetic MASH system

A series of experiments was conducted on the decomposition of natural and chemically mixed chlorites to examine the stable hydrous phases in the MgO–FeO–Al₂O₃–SiO₂–H₂O (MFASH) system under 5–12 GPa and 700–1100 °C. The upper pressure and temperature limits of the stability region of chlorite are consistent with those observed in previous studies. The hydrous aluminum bearing pyroxene (phase HAPY) and Mg-sursassite (Sur) were observed just above the temperature stability region of chlorite (Chl); clinohumite (cHm) was observed coexisting with phase HAPY at 6 GPa and 800 °C and coexisting with the 23-Å phase at 7 GPa and 800 °C, which may suggest the transportation of water through Chl → (HAPY → cHm) → 23-Å phase along a relatively warm slab. The 23-Å phase has a wider stability region in the pure MASH system (up to 12 GPa and 1100 °C) than it does in the MFASH system (7–10 GPa, up to 1000 °C). The stability of the 23-Å phase beyond the chlorite breakdown pressure indicates that it may play an important role in transporting water into the deep Earth and even into the mantle transition zone.     

Metal contents in Porites corals: Anthropogenic input of river run-off into a coral reef from an urbanized area, Okinawa

In order to monitor pollutants from urban areas to coral reefs, metal contents in Porites coral samples collected from the Hija River mouth and at nearby sites from the estuary were analyzed. The corals were cleaned by oxidative and reductive treatments to effectively eliminate detritus and organic materials. Metal-to-calcium (Me/Ca) ratios in the samples were determined by ICP-MS. Filtered samples of river water were also measured similarly for metal concentrations. The extent of anthropogenic contribution by riverine input was assessed by comparing the Me/Ca values in corals to those of Rukan-sho, an unpolluted coral reef. High riverine inputs of Mn, Cd, Zn and Ag were observed from Me/Ca values in the coral samples. Manganese in the coral samples showed strong dependence on salinity, varying inversely to the distance from terrestrial sources. Considering a lead background of 25.0 nmol/mol measured in the Rukan-sho corals, Pb/Ca in corals of the Hija River estuary that are two and three times higher may indicate lead enrichment in the river mouth. Because Pb is only moderately high in the Hija River water compared to its concentration in surface seawater, lead may have accumulated in the estuarine water and sediments, resulting in an elevated concentration of lead available for coral uptake.     

Climate change impacts on international seaports: knowledge, perceptions, and planning efforts among port administrators

Seaports are located in vulnerable areas to climate change impacts: on coasts susceptible to sea-level rise and storms or at mouths of rivers susceptible to flooding. They serve a vital function within the local, regional, and global economy. Their locations in the heart of sensitive estuarine environments make it an imperative to minimize the impacts of natural hazards. Climate impacts, like a projected SLR of .6?m to 2?m and doubling of Category 4 and 5 hurricanes by 2100, will result in more extreme events at many seaports. To assess the current state of knowledge on this issue, we surveyed port authorities from around the world about how administrators felt climate change might impact their operations, what sea-level change would create operational problems, and how they planned to adapt to new environmental conditions. The planned rapid expansion of ports reported by the survey respondents indicates that adaptation measures should be considered as ports construct new infrastructure that may still be in use at the end of the century. Respondents agreed that the ports community needs to address this issue and most felt relatively uninformed about potential climate impacts. Although most ports felt that SLR would not be an issue at their port this century, sea-level rise was nevertheless an issue of great concern. Our results suggest opportunities for the scientific community to engage with port practitioners to prepare proactively for climate change impacts on this sector.     

Study on the Historical Distribution of Metals in Aquatic Sediments

In this study, the historical distribution of metals, phosphorous, and sulfur at four different depths in the sediments of different lakes formed in the course of an urban river (in Londrina, Parana State, Brazil) were determined. The transport of metals along the course of the river was observed mainly for Mn, Cr, and Zn. High concentrations of Pb in the Capivara Bay and Cr in the river were attributed to contamination from a battery plant and a tannery, respectively. The concentrations of heavy metals in the deepest layers of the sediments remain high several years after deposition.     

Assessing land-use and carbon stock in slash-and-burn ecosystems in tropical mountain of Laos based on time-series satellite images

In the tropical mountains of Southeast Asia, slash-and-burn (S/B) agriculture is a widely practiced and important food production system. The ecosystem carbon stock in this land-use is linked not only to the carbon exchange with the atmosphere but also with food and resource security. The objective of this study was to provide quantitative information on the land-use and ecosystem carbon stock in the region as well as to infer the impacts of alternative land-use and ecosystem management scenarios on the carbon sequestration potential at a regional scale. The study area was selected in a typical slash-and-burn region in the northern part of Laos. The chrono-sequential changes of land-use such as the relative areas of community age and cropping (C) + fallow (F) patterns were derived from the analysis of time-series satellite images. The chrono-sequential analysis showed that a consistent increase of S/B area during the past three decades and a rapid increase after 1990. Approximately 37% of the whole area was with the community age of 1–5 years, whereas 10% for 6–10 years in 2004. The ecosystem carbon stock at a regional scale was estimated by synthesizing the land-use patterns and semi-empirical carbon stock model derived from in situ measurements where the community age was used as a clue to the linkage. The ecosystem carbon stock in the region was strongly affected by the land-use patterns; the temporal average of carbon stock in 1C + 10F cycles, for example, was greater by 33 MgC ha⁻¹ compared to that in 1C + 2F land-use pattern. The amount of carbon lost from the regional ecosystems during 1990–2004 periods was estimated to be 42 MgC ha⁻¹. The study approach proved to be useful especially in such regions with low data-availability and accessibility. This study revealed the dynamic change of land-use and ecosystem carbon stock in the tropical mountain of Laos as affected by land-use. Results suggest the significant potential of carbon sequestration through changing land-use and ecosystem management scenarios. These quantitative estimates would be useful to better understand and manage the land-use and ecosystem carbon stock towards higher sustainability and food security in similar ecosystems.